Fulminant Disseminating Fatal Granulomatous Amebic Encephalitis: The First Case Report in an Immunocompetent Patient in South Korea

Central nervous system infections caused by free-living amoeba are very rare, but often fatal. The typical image findings of amebic meningoencephalitis are non-specific, showing ring-like enhancement. We report the first case of fulminant disseminating fatal granulomatous amebic encephalitis caused by Balamuthia mandrillaris in an immunocompetent patient in South Korea. Our case exhibited two interesting features: one was the unusual clinical course and the other was additional image findings. Magnetic resonance imaging revealed a rim-enhancing lesion with intralesional blooming dark signal intensity on susceptibility weighted imaging and low signal intensity on diffusion weighted images and on apparent diffusion coefficient maps. Differential diagnosis was started from a tumor or non-tumorous lesion, and diagnosis was difficult due to the rarity of the disease. Following the clinical and diagnostic courses of our case, we recommend inspecting image findings of granulomatous amebic encephalitis for early diagnosis.

Acute Acquired Metabolic Encephalopathy Based on Diffusion MRI

Metabolic encephalopathy is a critical condition that can be challenging to diagnose. Imaging provides early clues to confirm clinical suspicions and plays an important role in the diagnosis, assessment of the response to therapy, and prognosis prediction. Diffusion-weighted imaging is a sensitive technique used to evaluate metabolic encephalopathy at an early stage.Metabolic encephalopathies often involve the deep regions of the gray matter because they have high energy requirements and are susceptible to metabolic disturbances. Understanding the imaging patterns of various metabolic encephalopathies can help narrow the differential diagnosis and improve the prognosis of patients by initiating proper treatment regimen early.

Susceptibility-Weighted Imaging as a Distinctive Imaging Technique for Providing Complementary Information for Precise Diagnosis of Neurologic Disorder

Various sequences have been developed for MRI to aid in the radiologic diagnosis. Among the various MR sequences, susceptibility-weighted imaging (SWI) is a high-spatial-resolution, threedimensional gradient-echo MR sequence, which is very sensitive in detecting deoxyhemoglobin, ferritin, hemosiderin, and bone minerals through local magnetic field distortion. In this regard, SWI has been used for the diagnosis and treatment of various neurologic disorders, and the improved image quality has enabled to acquire more useful information for radiologists.Here, we explain the principle of various signals on SWI arising in neurological disorders and provide a retrospective review of many cases of clinically or pathologically proven disease or components with distinctive imaging features of various neurological diseases. Additionally, we outline a short and condensed overview of principles of SWI in relation to neurological disorders and describe various cases with characteristic imaging features on SWI. There are many different types diseases involving the brain parenchyma, and they have distinct SWI features.SWI is an effective imaging tool that provides complementary information for the diagnosis of various diseases.

Pituitary Metastasis of Bronchial Carcinoid Tumor Mimicking Pituitary Adenoma: a Case Report

Tumors that metastasize to the pituitary gland are unusual and metastasis of neuroendocrine neoplasm to the sellar region is extremely rare. We report a 59-yearold man with pituitary metastasis from pulmonary carcinoid tumor who presented with left progressive deterioration of visual field. Sellar dynamic magnetic resonance imaging revealed an enhancing sellar mass invading the left cavernous sinus. We report this unusual case with a review of the relevant literature.

Fulminant Disseminating Fatal Granulomatous Amebic Encephalitis: The First Case Report in an Immunocompetent Patient in South Korea

Central nervous system infections caused by free-living amoeba are very rare, but often fatal. The typical image findings of amebic meningoencephalitis are non-specific, showing ring-like enhancement. We report the first case of fulminant disseminating fatal granulomatous amebic encephalitis caused by Balamuthia mandrillaris in an immunocompetent patient in South Korea. Our case exhibited two interesting features: one was the unusual clinical course and the other was additional image findings. Magnetic resonance imaging revealed a rim-enhancing lesion with intralesional blooming dark signal intensity on susceptibility weighted imaging and low signal intensity on diffusion weighted images and on apparent diffusion coefficient maps. Differential diagnosis was started from a tumor or non-tumorous lesion, and diagnosis was difficult due to the rarity of the disease. Following the clinical and diagnostic courses of our case, we recommend inspecting image findings of granulomatous amebic encephalitis for early diagnosis.

Pituitary Metastasis of Bronchial Carcinoid Tumor Mimicking Pituitary Adenoma: a Case Report

Tumors that metastasize to the pituitary gland are unusual and metastasis of neuroendocrine neoplasm to the sellar region is extremely rare. We report a 59-yearold man with pituitary metastasis from pulmonary carcinoid tumor who presented with left progressive deterioration of visual field. Sellar dynamic magnetic resonance imaging revealed an enhancing sellar mass invading the left cavernous sinus. We report this unusual case with a review of the relevant literature.

A Case of Isolated Nodular Infarction Mimicking Vestibular Neuritis on the Contralateral Side

Differentiating central vestibulopathy from more common vestibular disorders is crucial because it often necessitates different treatment strategies, and early detection can help to minimize potential complications. Isolated nodular infarct is one of the central brain lesions that can mimic peripheral vertigo. We present a case of isolated nodular infarct that had been misdiagnosed as vestibular neuritis on the contralateral side at the initial evaluation. The patient was successfully treated with anticoagulants and antihyperlipidemic agents. Clinicians should keep in mind that some causes of central vertigo mimic peripheral vestibulopathy at the early stage.

Schwannoma of the Tongue Base with Imaging Features and Differential Diagnosis: a Rare Case Report and Literature Review

Schwannoma or neurilemmoma is a benign peripheral nerve sheath tumor that arises from Schwann cells. Approximately 25–45% of all schwannomas occur in the head and neck regions, and the intraoral presentation of these is only 1%. We report a rare case of a patient presenting tongue base schwannoma with characteristic imaging features on computed tomography and magnetic resonance imaging.

Imaging Features and Pathologic Correlation of Papillary Meningioma: A Case Report

Papillary meningioma is rare meningeal tumors and is associated with aggressive clinical behavior as compared with other meningiomas. We report a case of papillary meningioma in a 50-year-old woman presented with complaints of headache, nausea and vomiting. MRI revealed a very macrolobulated heterogeneously enhancing solid mass at the right frontal convexity with focal prominent inward infiltrating portion and surrounding moderate brain edema. The localization of the lesion as intra-axial or extra-axial in origin was difficult. Demonstrated diffusion restriction and high relative cerebral blood volume value were similar to conventional meningioma, but hypervascular inward infiltrating portion could be seen in papillary meningioma. The histopathology examination of the resected tissues revealed papillary meningioma with an increased cellularity and high nuclear/cytoplasm ratio. She underwent radical excision of the tumor, followed radiotherapy and tumor recurrence occurred at 12 months later.

MRI Features of Atypical Cavernous Hemangioma Showing Central Filling Defect: A Case Report

Cavernous hemangioma is a benign tumor composed of vascular structures and connective tissue. Typical imaging findings of cavernous sinus cavernous hemangioma are a well-defined contour-bulging mass, with homogeneous high signal intensity on T2-weighted images (T2WI), marked homogeneous enhancement of the cavernous sinus, and some sellar extension on magnetic resonance images. However, we experienced an unusual case of cavernous hemangioma, with central filling defects on delayed contrast-enhanced T1-weighted images and central, dark signal intensities on T2WI, which made the diagnosis difficult. The central portion of the lesion was pathologically consistent with central thrombosis. We present the clinical and imaging findings of this unusual case of cavernous hemangioma.

Unrecognised IgG4 association in progressively transformed germinal centers of lymph nodes with subsequent full-blown IgG4-related chronic fibrosing pancreatitis: A case report

Progressively transformed germinal centers (PTGC) is a benign process characterised by a morphological variant of reactive follicular hyperplasia in lymph nodes. It was recently shown that some cases of PTGC are associated with IgG4-related disease (IgG4-RD) or increased IgG4 plasma cells. Five years ago, a 57-year-old woman presented with enlargement of multiple lymph nodes in the left parotid, submandibular, and neck areas, pathologically diagnosed as PTGC after excisional biopsy. Since then, she has experienced numbness in her extremities, especially the left shoulder and arm, pruritus on the left side of the face and intermittent facial palsy, for which she has been receiving regular symptomatic treatment. Recently the patient developed diabetes mellitus (approximately seven months ago). In routine follow-up scans, a mass was detected in left kidney and magnetic resonance imaging of the abdomen prior to surgery revealed a slightly enhanced bulky mass replacing the pancreatic tail and uncinate process. The mass in left kidney was diagnosed as clear cell renal cell carcinoma, and the pathological features of the pancreatic lesion were those of IgG4-related chronic fibrosing pancreatitis. Retrograde examination of the neck lymph node diagnosed as PTGC showed increased deposition of IgG4-positive plasma cells.

Cerebral Venous Thrombosis Complicated by Intracranial Hypotension

Intracranial hypotension caused by cerebral venous thrombosis has rarely been reported. We report a patient with cerebral venous thrombosis with intracerebral hemorrhage complicated by intracranial hypotension. Initial manifestations were headache, drowsy mentality, generalized tonic-clonic seizure and left-sided weakness. The pattern of headache changed and typical orthostatic headache developed after anticoagulation following endovascular thrombolysis. If an orthostatic headache develops in patient with cerebral venous thrombosis, subsequent intracranial hypotension may be considered.

A Case of Immune Reconstitution Inflammatory Syndrome in AIDS-related Progressive Multifocal Leukoencephalopathy after Antiretroviral Therapy / 감염과화학요법

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system due to JC virus. In acquired immunodeficiency syndrome (AIDS) patients, JC virus infects myelin-producing oligodendrocytes causing a non-inflammatory lytic reaction leading to demyelination and brain death. We herein report a case of a 56-years-old AIDS man who developed immune reconstitution inflammatory syndrome and died while undergoing highly active antiretroviral therapy. In this patient, the PML involved the brainstem, causing mental confusion followed by recurrent aspiration, adult respiratory distress syndrome, and eventually to early death.

Intracranial Lesions in a Patient With Carney Complex

Carney complex (CNC) is an autosomal dominant disorder that involves the heart, multiple endocrine systems, testis, skin, breast, and bone. We report a case of a 38-year-old woman, diagnosed with CNC, with a mass involving the petrous bone, a pituitary adenoma, a cavernous angioma, multiple cerebral aneurysms, and venous malformations. CNC should be included in the differential diagnoses of patients who have an atrial myxoma, brain tumor, or intracranial vascular malformations.

Metronidazole-Induced Toxic Encephalopathy in A Hemodialysis Patient: A Case Report / 대한신장학회지

Metronidazole, one of the mainstay drugs for the treatment of anaerobic infections and protozoal infections, may produce some serious neurological side effects. Seizure, peripheral neuropathy, dizziness, vertigo, ataxia, confusion, irritability, headache and tremor have been reported among patients receiving metronidazole, particularly among those receiving high dose of the drug. However, no specific dose adjustment is recommended for patients with renal or hepatic dysfunction receiving metronidazole because the accumulation of the drug and its metabolites can occur in terms of severity of illness and patient tolerability. Although metronidazole is significantly removed by hemodialysis, no specific dose recommendations are made for this patient population. Recently, we experienced metronidazole-induced encephalopathy in a patient with end-stage renal disease, which was diagnosed by brain magnetic resonance imaging (MRI). Herein, we report a case with a review of literature.

The Differences of the Magnetic Resonance Spectroscopy Findings Between a Subacute Infarction and a Malignant Glioma with a Similar Mass-Like Enhancing Lesion

PURPOSE: We evaluated the usefulness of magnetic resonance spectroscopy (MRS) method to differentiate the mass-like enhancing subacute infarction from malignant gliomas. MATERIALS AND METHODS: Twenty patients (M:F =11:9, mean age: 56.1 yrs) with mass-like enhancing lesions (via an MRI) were studied. Ten of the twenty patients suffered a subacute infarction, whereas the other ten had malignant gliomas. The subacute infarctions were confirmed clinically by a follow-up MRI, while malignant gliomas were confirmed via surgical biopsies. We checked the metabolite peak intensity (Choline [Cho], Creatine [Cr], N-acetyl-aspartate [NAA]) and the metabolite ratios (Cho/Cr, NAA/Cr) of (1)H MRS data, obtained on mass-like enhancing lesion in subacute infarction and malignant glioma. RESULTS: Of the (1)H MRS confirmed, the subacute infarctions (10 cases), three metabolites were identified at peak intensity (NAA, Cho and Cr peak intensity), which decreased below the normal value, while eight of ten patients (80%) of the malignant gliomas, showed a noticeable increase in Cho peak intensity, with decreased NAA and Cr peak intensity. The Cho peak intensity was statistically different between the two groups (p < 0.05). The two groups revealed that all increased Cho/Cr ratio; however, the malignant glioma group showed an increase in Cho/Cr ratio over the subacute infarction group (p < 0.05). CONCLUSION: The MRS findings revealed that the decreased Cho level, as well as the slightly increased Cho/Cr ratio on the mass-like enhancing lesion, suggests a subacute infarction rather than a malignant glioma.

Pneumocephalus in Patients With Orthostatic Headache

Cerebrospinal fluid (CSF) leak or shunt overdrainage is a well-known cause of orthostatic headaches and low CSF pressures. We report two cases of orthostatic headache with pneumocephalus on brain imaging. The orthostatic headache developed after drainage of spinal operation site and epidural block. Brain MRI revealed characteristic findings of CSF hypovolemia including pachymeningeal enhancement and mild subdural fluid collections. Air was also observed in the ventricular or subarachnoid space in both patients, which might enter the subarachnoid or ventricular space during a procedure via the pressure gradient or an injection.

Comparison of Diffusion Tensor Imaging in Attention Deficit Hyperactivity Disorder Boys with or without Comorbid Tic Disorders / 신경정신의학

OBJECTIVES: Diffuse tensor imaging (DTI) was applied to explore the difference in regional distribution and extent of white matter (WM) abnormalities in boys with Attention-deficit/hyperactivity disorder (ADHD) versus boys with comorbid ADHD and tic disorders. METHODS: Fifteen boys with ADHD (mean age 9.3+/-1.8), 24 ADHD boys with chronic tic disorder or Tourette's disorder (9.9+/-1.2) and 9 age-, gender-matched controls (9.2+/-1.8) received DTI assessments. Fractional Anisotropy (FA) maps of WM were compared between groups with a voxel-wise analysis after intersubject registration to MNI space. RESULTS: Both groups, ADHD group and ADHD with tic disorder group, commonly showed decreased FA than healthy control group in left cerebellar middle peduncle and right frontal lobe, increased FA in right middle occipital WM. In the common areas of left cerebellar middle peduncle and right middle occipital WM, comorbid group showed broader areas of significant FA. The comorbid group also showed increased FA in right cerebellar peduncle, additionally. CONCLUSION: The findings in ADHD group support previous ADHD hypothesis of the functional abnormalities in corticocerebellar circuit, and suggest that ADHD might have more complicated pathology of neuronal circuit including occipital visual system. The comorbid group showed common areas of overlapping but more extensive abnormalities and also had additional WM abnormalities. ADHD with chronic tic disorders may represent a severe form of ADHD with additional regions of abnormal connectivity.

Cognitive Dysfunction in 16 Patients with Carotid Stenosis: Detailed Neuropsychological Findings

BACKGROUND: Impairment of cognitive function is often present in patients with carotid artery stenosis but the details of this dysfunction have rarely been reported. Our purpose was to elucidate the cognitive dysfunction in patients with unilateral severe carotid stenosis using comprehensive neuropsychological testing, and also to identify the specific underlying clinical and radiological factors. METHODS: We analyzed the results of neuropsychological testing, the clinical history, and MR findings in 16 consecutive patients with angiographically proven severe (70-99%) stenosis of the extra cranial internal carotid artery (ICA). Cognitive functions were examined using the Seoul Neuropsychological Screening Battery and the Neglect Battery. We excluded patients with cortical infarction and those with contra lateral ICA occlusion or severe stenosis. RESULTS: Our comprehensive neuropsychological testing revealed obvious cognitive deficits in all patients with unilateral severe ICA stenosis, the most common being frontal executive impairment. The mean cognitive score on the memory test was also significantly lower in patients with symptomatic ICA stenosis than in asymptomatic patients (29.33+/-10.98, mean+/-SD, p < 0.05). The total score on the global cognitive test was significantly lower in patients with an ischemic lesion on MRI than in no lesion patients (113.23+/-34.78, p < 0.05). The presence of symptoms related to the ICA stenosis was related to cognitive dysfunction even when there were no ischemic lesions on MRI. SPECT revealed ipsilateral cortical hypoperfusion in 9 of 12 patients (75%). CONCLUSIONS: Cognitive deficits are common in patients with unilateral severe ICA stenosis. Our findings suggest that an additional mechanism beyond the structural lesion such as chronic hypoperfusion may affect cognitive function in patients with high-grade ICA stenosis.

Diffusion-Weighted MRI in Recurrent Wernicke's Encephalopathy: a Remarkable Cerebellar Lesion

We report unusual MRI findings (including those from diffusion-weighted imaging (DWI)) in a patient with recurrent Wernicke's encephalopathy with a remarkable cerebellar lesion. DWI showed high signal intensities in the superior portion of the cerebellar hemisphere and vermis area. After thiamine administration, clinical symptoms improved and the lesions with high signal intensities disappeared on follow-up DWI.